21252880 has 40 divisors (see below), whose sum is σ = 53907264. Its totient is φ = 7728000.

The previous prime is 21252871. The next prime is 21252893. The reversal of 21252880 is 8825212.

It is a tau number, because it is divible by the number of its divisors (40).

It is a Smith number, since the sum of its digits (28) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11196 + ... + 12955.

Almost surely, 2^21252880 is an apocalyptic number.

21252880 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21252880 is an abundant number, since it is smaller than the sum of its proper divisors (32654384).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21252880 is a wasteful number, since it uses less digits than its factorization.

21252880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24175 (or 24169 counting only the distinct ones).

The product of its (nonzero) digits is 2560, while the sum is 28.

The square root of 21252880 is about 4610.0845979223. The cubic root of 21252880 is about 276.9954253829.

It can be divided in two parts, 2125 and 2880, that added together give a palindrome (5005).

The spelling of 21252880 in words is "twenty-one million, two hundred fifty-two thousand, eight hundred eighty".